/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.engine.querycontext;

import org.apache.iotdb.db.exception.query.QueryProcessException;
import org.apache.iotdb.db.query.reader.chunk.MemChunkLoader;
import org.apache.iotdb.db.utils.datastructure.TVList;
import org.apache.iotdb.tsfile.common.conf.TSFileDescriptor;
import org.apache.iotdb.tsfile.encoding.encoder.Encoder;
import org.apache.iotdb.tsfile.file.metadata.ChunkMetadata;
import org.apache.iotdb.tsfile.file.metadata.IChunkMetadata;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
import org.apache.iotdb.tsfile.file.metadata.statistics.Statistics;
import org.apache.iotdb.tsfile.read.common.TimeRange;
import org.apache.iotdb.tsfile.read.common.block.TsBlock;
import org.apache.iotdb.tsfile.read.reader.IPointReader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.List;
import java.util.Map;

/**
 * ReadOnlyMemChunk is a snapshot of the working MemTable and flushing memtable in the memory used
 * for querying
 */
public class ReadOnlyMemChunk {

    private String measurementUid;

    private TSDataType dataType;

    private static final Logger logger = LoggerFactory.getLogger(ReadOnlyMemChunk.class);

    protected IChunkMetadata cachedMetaData;

    protected TsBlock tsBlock;

    protected ReadOnlyMemChunk() {
    }

    public ReadOnlyMemChunk(
            String measurementUid,
            TSDataType dataType,
            TSEncoding encoding,
            TVList tvList,
            Map<String, String> props,
            List<TimeRange> deletionList)
            throws IOException, QueryProcessException {
        this.measurementUid = measurementUid;
        this.dataType = dataType;
        int floatPrecision = TSFileDescriptor.getInstance().getConfig().getFloatPrecision();
        if (props != null && props.containsKey(Encoder.MAX_POINT_NUMBER)) {
            try {
                floatPrecision = Integer.parseInt(props.get(Encoder.MAX_POINT_NUMBER));
            } catch (NumberFormatException e) {
                logger.warn(
                        "The format of MAX_POINT_NUMBER {}  is not correct."
                                + " Using default float precision.",
                        props.get(Encoder.MAX_POINT_NUMBER));
            }
            if (floatPrecision < 0) {
                logger.warn(
                        "The MAX_POINT_NUMBER shouldn't be less than 0." + " Using default float precision {}.",
                        TSFileDescriptor.getInstance().getConfig().getFloatPrecision());
                floatPrecision = TSFileDescriptor.getInstance().getConfig().getFloatPrecision();
            }
        }
        this.tsBlock = tvList.buildTsBlock(floatPrecision, encoding, deletionList);
        initChunkMetaFromTsBlock();
    }

    private void initChunkMetaFromTsBlock() throws IOException, QueryProcessException {
        Statistics statsByType = Statistics.getStatsByType(dataType);
        IChunkMetadata metaData = new ChunkMetadata(measurementUid, dataType, 0, statsByType);
        if (!isEmpty()) {
            switch (dataType) {
                case BOOLEAN:
                    for (int i = 0; i < tsBlock.getPositionCount(); i++) {
                        statsByType.update(tsBlock.getTimeByIndex(i), tsBlock.getColumn(0).getBoolean(i));
                    }
                    break;
                case TEXT:
                    for (int i = 0; i < tsBlock.getPositionCount(); i++) {
                        statsByType.update(tsBlock.getTimeByIndex(i), tsBlock.getColumn(0).getBinary(i));
                    }
                    break;
                case FLOAT:
                    for (int i = 0; i < tsBlock.getPositionCount(); i++) {
                        statsByType.update(tsBlock.getTimeByIndex(i), tsBlock.getColumn(0).getFloat(i));
                    }
                    break;
                case INT32:
                    for (int i = 0; i < tsBlock.getPositionCount(); i++) {
                        statsByType.update(tsBlock.getTimeByIndex(i), tsBlock.getColumn(0).getInt(i));
                    }
                    break;
                case INT64:
                    for (int i = 0; i < tsBlock.getPositionCount(); i++) {
                        statsByType.update(tsBlock.getTimeByIndex(i), tsBlock.getColumn(0).getLong(i));
                    }
                    break;
                case DOUBLE:
                    for (int i = 0; i < tsBlock.getPositionCount(); i++) {
                        statsByType.update(tsBlock.getTimeByIndex(i), tsBlock.getColumn(0).getDouble(i));
                    }
                    break;
                default:
                    throw new QueryProcessException("Unsupported data type:" + dataType);
            }
        }
        statsByType.setEmpty(isEmpty());
        metaData.setChunkLoader(new MemChunkLoader(this));
        metaData.setVersion(Long.MAX_VALUE);
        cachedMetaData = metaData;
    }

    public TSDataType getDataType() {
        return dataType;
    }

    public boolean isEmpty() throws IOException {
        return tsBlock.isEmpty();
    }

    public IChunkMetadata getChunkMetaData() {
        return cachedMetaData;
    }

    public IPointReader getPointReader() {
        return tsBlock.getTsBlockSingleColumnIterator();
    }

    public TsBlock getTsBlock() {
        return tsBlock;
    }
}
